Lets run an app on the atomic systems we deployed earlier
We'll use the Cockpit admin interface
it includes a dashboard to drive your cluster directly
Modern apps are structured around micro-services
that run in separate containers
Kubernetes is what we'll use to orchestrate the containers of our app
Atomic supports kubernetes
out of the box
Nulecule is a way of delivering and
packaging these containerized apps
Lets type the name of our application
Namespaces are a way of partitioning
your cluster so that
different apps and projects can run separately
The app is getting pulled down
and extracted
Now we see that it requires
a bit of configuration before we can go
We need a public IP address to run at
and we're ready!
Now it's instantiating the services,
pulling the containers, starting them up
If you wanted to develop
a kubernetes based application,
you would use Openshift
But here we've taken an example app
that's already built and deployed it
Now that it's started up,
we can verify that it's working
It's a simple guestbook
It just stores values
But under the covers it's a bit more complicated than that
Lets look at the containers
that make up this application
Here you can see the various containers
that have been started
They're running this image
There's multiple instances
Redis is running
both a master and a slave
This is the console of a redis container
We can pop into a shell inside containers
wherever they are running
This container is running a Go application
You'll notice all these containers
were started on a single node
That's not what you would call a "cluster"
Lets add some more atomic nodes
We set these up in an earlier demo
To prove that I'm actually just
running kubernetes commands
I'm going to add a node
from the command line
You can see the nodes starting up
We can scale our application out
across those different nodes
Lets have six frontend containers
and maybe 3 Redis slaves
The containers are starting up
The resource usage is starting to rise
Lets take a look at the moving parts
What is happening inside Kubernetes
Things are alive,
scurrying around and interacting
You can hide stuff,
if it makes the view clearer
and drag stuff around
Here we see a service, the Redis slave
listening on this IP
It's routing requests to these pods here
and its using this image
This pod is on this node
Pods are groups of containers
There's just one container in this pod
If we start an application,
this time from the command line
you can see everything coming to life
in kubernetes and getting connected
These services are not routing
to any pods yet
You can see them getting hooked up
as the application comes up
I hope you've enjoyed this
look at Kubernetes and Cockpit